GSK- J4 is cell-permeable ethyl ester of GSK-J1 (Cat. Nos. 2260 & 2761). Acts as a histone demethylase JMJD3/UTX inhibitor. Inhibits demethylation of histone H3K27. Reduces LPS-induced proinflammatory cytokine production in primary human macrophages (IC₅₀ = 9 μM for the inhibition of TNFα release). Rescues newborn pups from embryonic lethality in BRAF knockin mice which recapitulate major features of RASopathies.